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05-15-2008, 05:08 AM   #1
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Expectations too high or something wrong.

I have noticed that my 50mm is noticeably soft and have been experimenting with charts etc to see if there is a backfocusing problem etc.

When wide open, shots are so blurred they are almost out of focus. I have even sent my lens back and had it changed thinking something was wrong - but the new one is not much better.

I have attached 3 images at 1.4 2.8 and 5.6, and they all show progressing sharpness, but at 1.4 its really bad. Is this other people experience ?

They were taken with flash about 3 feet away.

The photos are here as crops to make peoples life easier.
50mm Images - a set on Flickr

05-15-2008, 05:26 AM   #2
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the depth of field at f/1.4 is paper thin, as you said, as you narrow your DOF (higher f/stop) the sharpness increases. you have to be spot on on your focus at the wide end. i get the same results from my sigma f/1.8 in the wide end.
05-15-2008, 05:49 AM   #3
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so if the k10d is in AF - perhaps its focus needs adjusting?
05-15-2008, 06:07 AM   #4
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Looks to me like your focus is slightly closer than the target.

This is the current AF 50mm? I don't have one, but when I tried out my various Takumars I did feel 1.4 is a bit low contrast.

05-15-2008, 06:33 AM   #5
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yes - its the AF50mm 1.4 - which is known to be pretty good.

Perhaps its the camera + lens which need to be calibrated.

Anyone had experience of having this done in the UK? How long etc??
The camera only a few weeks old - I could get the body exchanged for a one easily but will I have the same problem?
05-15-2008, 06:37 AM   #6
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QuoteOriginally posted by NorrisTudor Quote
so if the k10d is in AF - perhaps its focus needs adjusting?
Your camera-lens combination is a little front-focusing. At f1,4 thats trouble.
Try manual focusing for the test (see the text that has to be seen clear, as clear as posible).
05-15-2008, 01:59 PM   #7
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The Pro Lloyd Chambers concluded that the Nikon D200 and D2X could not be relied upon for critical focus.

And a recent reviewer of Eos 1Ds Mark III stated how the Auto Focus was not as precise as what he could do himself via live view magnification.

If these cameras in several thousands dollar class cannot be trusted, chances are little is wrong with your camera or lens.
Klaus from PhotoZone tests his lenses via manual focus.

The 50/1.4 lens is not as sharp wide open as the FA limited lenses or FA* lenses, and not very much contrast wide open. It generally needs to be stopped down to achieve high sharpness.

If you want pin sharpness at f/1.4, then it is the Nikon D3 that is needed.

Here is the link to the professional nature and outdoor photographer Darwin Wiggett Auto Focus review of his Eos 1Ds Mark III :
Digital Photography

Remember the AF sensor on the K10 is bigger than the red light in the middle, so often you need 3D subjects to really test AF system. If you still have problem at f/4.5 or f/5.6, then it is more of a thing to get into. Darwin Wiggett even did his tests at f/2.8

If you want precise AF at f/1.4 you need to look at cameras in the 5.000 $ range

Last edited by Jonson PL; 05-15-2008 at 02:11 PM.

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